Megatron and the Decepticons were the ones who developed transformation first, using it to begin the war against the Autobots, who fought back by mimicking the technology.

Following a war between the Decepticons and the other robot race, the Autobots, the Decepticons were defeated by the Autobots ' invention of transformation.

Wounded Decepticons were set adrift in space including Megatron.

The Autobots and Decepticons were reactivated in 1984.

The Combaticons that formed Bruticus were the first of the Decepticons to be introduced into the show along with Scourge, who as a toy was a black repaint of G2 Laser Prime.

The Decepticons were designed instead with alternative " attack modes ".

Hasbro launched the Transformers toy line with ten different Autobot characters, all of whom transformed into automobiles, while the ten distinct Decepticons, ( seven packages as three came two to a box / pack ) were weapons, aircraft and communications equipment.

These Decepticons who left their homeworld became " The Second Generation " Decepticons, who were led by the villainous Liege Maximo.

In the original animated series continuity, the Decepticons owe their warlike ways to their faction's origin as military hardware robots, created by the five-faced aliens, the Quintessons, while the Autobots were designed as consumer goods.

After five million years, Cybertron was nearly depleted of all its energy when the Decepticons received word that the Autobots were planning to search for new energy resources.

Megatron eventually killed Prime one-on-one as a symbol, and the Decepticons were forged.

In this continuity, the Decepticons were not the name of the evil faction, but rather a sub-faction created by Megatron.

After Galvatron's defeat by Omega Prime, the Decepticons were among those sent back to Cybertron for imprisonment, except for Sky-Byte.

In Transformers: Revenge of the Fallen it is revealed that The Fallen, a Prime who turned evil, is the First leader and founder of the Decepticons, which would seem to imply the Decepticons were originally Autobots who turned evil.

Although the United Kingdom's exclusive Transformers comic series shone the spotlight on the Constructicons when they were charged with hunting down Buster Witwicky, and again when the time-travelling Galvatron co-opted their services to build a gigantic laser cannon, the team's special talents were not required in the US title again until they and the Predacons stole large amounts of rocket fuel and raw materials, with which the Constructicons rebuilt the Decepticons ' mobile island headquarters as a spaceship.

As a friend of the Constructicons, he was hurt the most when they were attacked by Megatron, who, seeking to bolster the forces of his then-small army, subjected the Constructicons to the Robo-Smasher, a device which reprogrammed their minds and turned them into Decepticons.

Eventually, he succeeded in capturing them and apparently restored their programming to its original state, but as the group returned to rebuild Crystal City, Omega learned that Megatron's reprogramming could never be undone — the Constructicons were still Decepticons, and more than that, Megatron had given them a new power: the ability to combine their bodies and minds into the giant known as Devastator.

They and the other Decepticons were then forced into a river of lava.

The Constructicons merged into Devastator to stop the Autobots from gaining an energy source the Decepticons were attempting to find, but were defeated by Grimlock.

1. 5 million years later, when Megatron and Optimus Prime were thought to have died in an early test of the Space Bridge transport system, and the Autobots and Decepticons splintered into several smaller factions, the Constructicons broke the treaty that had downgraded the combining teams to non-combat status by siding with Ratbat's Ultracons and battling Defensor.

Soundwave helped him in recovering the body of Astrotrain, who was then used to help locate the placement of other fallen Decepticons around the globe.

The Decepticons would then be in a position to conquer whoever was the victor of that battle ...

The game takes on Cybertron during the Great War between the Autobots, led first by Zeta Prime and then Optimus Prime, and the Decepticons, led by Megatron.

Megatron turned on Pax and fatally injured him, but the ancient Autobot, Alpha Trion, then rebuilt Pax into the first of a new, battle-hardy breed of Autobot-now, he was Optimus Prime, leader of the Autobots, who led them against Megatron and the Decepticons as the civil war erupted once more.

The Decepticons then move in and harvest the world's raw resources.

Megatron then reclaims leadership of the Decepticons, keeping a strict eye on Starscream.

The Autobots and Maximals then go to the planet where they save the victims from the Decepticons.

Ironically, the Combaticons ended up taking control of Cybertron and altered the space bridge to push the Earth into then sun, achieving revenge on Megatron, the Autobots, the Decepticons, and the Earth.

He then attacks the Reapers single-handedly, forcing Megatron to lead the other Decepticons in assisting him.

Optimus becomes enraged at the price of gas, steals the fuel from the annoying hybrid Autobot Prius Maximus, then joins the Decepticons in destroying the city.

Little did Megatron suspect, however, that Starscream had evolved a new ambition – where in Armada he had sought little more than Megatron's respect, now he sought to oust Megatron and become the leader of the Decepticons, then the universe.

The Decepticons were revived first and then the Autobots due to Starscream's carelessness.

Megatron then reclaims leadership of the Decepticons, keeping a strict eye on Starscream.

With the aid of Sixshot, the Decepticons were then able to seize control of Cybertron's computer systems, enshrouding the surface of the planet in a poisonous Energon gas that kept the Autobots at a distance while the Energon Towers were used to propel Cybertron through the spatial rift, into the new region of space.

Once he arrived back at their base, Sentinel confirms of Sam's suspicions of the Decepticons ' plans, but then betrays the Autobots by revealing his affiliation with Megatron, and kills Ironhide with his cosmic rust cannon.

Soon after believing that the Autobots are gone, Sentinel Prime then betrays Megatron by taking command over the Decepticons, pushing Megatron away by demoralizing him in the process, and oversees the final phase of the plan in Chicago.

In a climatic moment, a furious Megatron intervenes in the battle by blasting Sentinel three times with his Fusion Shotgun, and then proceeds to knock his helmet off and ripping out a large portion of Sentinel's stomach armor with nothing more than his bare hands, and steals his sword, declaring it his revenge against Sentinel for taking over the Decepticons.

Prime then sends Omega Doom against the Decepticons.

The Decepticons then returned to Earth, and Scorponok began a plan to destroy the planet, which culminated in a battle between the entire Autobot and Decepticon armies at the North Pole.

The Decepticons then kidnapped Koji's friend, Carl, and used him to control Maximus.

The newly born Transformers then departed Earth to pursue the surviving Decepticons back into space.

Shockwave then turned Megatron upon Galvatron, but rather than destroy him, he saw a potential partner in Galvatron, and they teamed up to battle Autobots and Decepticons from both the present and future in the " Time Wars ", as a rift in the space-time continuum bore down on them.

Circuit Breaker then uses them to oppose the two Decepticons, who were attacking the Statue of Liberty.

After the first Decepticon ( Skywarp ) is revived, he immediately restores Megatron, who then orders the rest of the Decepticons to follow.